-r HYBRID alone muxed the HDR10/HDR10+ base layer as a standalone output because only the ingredient DV track was flagged hybrid_base_only. The inverse was also broken: HDR10/HDR10+/DV tracks never entered the standalone-deliverable pool, so -r HYBRID,HDR10P only delivered the standalone HDR10+ by accident of the first bug.
- Add Tracks.partition_hybrid_videos: ingredient ranges (HDR10/HDR10+/DV) enter the deliverable pool only when their range is explicitly requested alongside HYBRID; replaces the duplicated filter in dl.py.
- Add Tracks.flag_hybrid_ingredients: any track in the hybrid selection but not in the deliverable selection is flagged hybrid_base_only; replaces and generalises the DV-only dv_is_deliverable special case.
When -r included HYBRID, the dl pipeline only muxed the hybrid output and dropped every other downloaded range. DV was also treated purely as a hybrid ingredient pool, so an explicitly requested DV range never produced a standalone deliverable - only the lowest DV (the RPU ingredient) was selected.
- Select the best DV per resolution as a standalone deliverable when DV is in -r, while still using the lowest DV as the hybrid ingredient (dv_is_deliverable).
- Flag the ingredient-only DV (hybrid_base_only) so it is downloaded for the hybrid build but skipped during standalone muxing.
- Mux every requested range standalone after hybrid processing; build hybrids from deepcopied ingredients so the originals stay muxable.
- Add Tracks.merge_video_selections to de-dup the ingredient/deliverable overlap so a shared DV track is not downloaded or muxed twice.
Missing requested subtitle and audio languages now warn and continue when --best-available is set instead of hard-exiting. Without the flag, missing languages still produce an error and exit, matching the prior strict behavior. Audio missing-lang detection is now symmetric with subtitles.
- add find_missing_langs helper in core/utilities for reuse between s_lang and a_lang paths (skips all/best/orig sentinels)
- refactor dl.py s_lang/a_lang checks to share the helper
- add tests/lang_selection covering match primitives, helper output, and tricky langcodes corners (zh-Hans/zh-Hant/zh-CN/zh-TW/zh-HK, cmn/yue, fil/tl/tgl)
- clean up unused-var ruff F841 in tests/remote/unit/
Covers RemoteClient/RemoteService, REST routes, handlers, SessionStore, InputBridge, DownloadQueueManager, errors, compression, and serve CLI. E2e tier opts in via --live and can auto-spawn its own serve.
